Lock-nut.



' I. 1). ZITZERMAN.

LOOK NUT.

APPLICATION FILED SEPT. 26, 1912.

I TOR Isaac .DZ'i ze rmom By W , ATTORNEYS ISAAC D. ZITZERMAN, OF KANSAS CITY, MISSOURI.

LOCK-NUT.

Specification of Letters Patent.

Patented May 27, 1913.

Application filed September 26, 1912. Serial No. 722,437.

To all whom it may concern Be it known that I, ISAAC D. ZITZERMAN, a citizen of the United States, and a resident of Kansas City, in the county of Jackson and State of Missouri, have invented a new and Improved Lock-Nut, of which the following is a full, clear, and exact description.

The invention relates to lock nuts to be employed wit-h the ordinary nuts of bolts in railway oints, and in other situations where nuts are subjected to vibration.

My invention relates particularly to concave lock nuts.

It is a design of my invention to provide a lock nut having a concave side and in which the threads will be free from mutilation at thti. concave side and thus readily engage a ho t.

It is furthermore a design of the invenafter to be given.

Reference is to be had to the accompanying drawings forming a part of this specification, in which corresponding characters of reference indicate corresponding parts in all the views.

Figure 1 is a rear view of a lock nut embodying my invention; Fig. 2 is a cross section; Fig. 3 is a rear view of a different form of the improved locknut more particularly adapted for use in connection with faced nuts; Fig. 1 is a cross section of the form shown in Fig. 3; and Fig. 5 is a side elevation showing my improved lock nut applied to a bolt or nut, and two members clamped thereby, said members being shown in section.

Referring especially to the form shown in means in the form of two segmental or crescent-shaped ribs 13, concentric with the threaded eye or bore 12, and the said ribs are of such shape in cross section as to present a comparatively sharp edge 14 concentrio with the eye 12. Preferably the edge is formed by producing the outer side of the rib perpendicular to the inner face 16 of the lock nut, and forming the front face 17 of the rib at a slightly acute angle to the outer wall 15, the said face 17 being at an angle also to the inner side wall 18 of the rib, preferably an obtuse angle; the result is that the rib will have a sufficiently sharp edge 14: to properly engage the face of a nut, as 20, to be locked.

It will be seen from Figs. 1 and 2 that the concave form given to the nut is produced without mutilating the thread at the inner concave face of the nut, but on the contrary the thread extends continuously from the point of entrance 21 to the interior of the eye, while in certain known forms of lock nuts concavity is produced at the expense of the threads, the concaved lines cutting the threads and mutilating the Same, producing separated portions of the thread at diametrically opposite sides of the eye, the result being that difliculty and inconvenience are experienced in engaging the lock nut with the threads of a bolt.

In practice, the bolt as 22, is passed through the members to be clamped, such as elements 28, 24. An ordinary nut 20 is then run onto the bolt against the face of the outer element 24, and the lock nut takes onto the bolt outside of the nut 20. When the edges 14L of the ribs 13 come to a bearing against the outer face of the nut 20, the further turning of the lock nut causes the ribs to engage the nut 20 at diametrically opposite points, or substantially so, and the further screwing up of the lock nut will cause it to flat-ten out and assume a plane parallel with the innernut, or approximately so, the changing of the form of the lock nut from the concave form to the flattened form serving to effectively bind the lock nut on the threads of the bolt, as will readily be understood. The nut being bodily concaved, and therefore not having its thickness reduced at any point, and being provided with the faces 11, the lock nut lends itself eflectively to the engagement of a wrench, and

no difficulty is experienced by slipping of the Wrench.

The described form is particularly efiicient with unfaced inner nuts, as the separate concentric ribs 13 accommodate the lock nut to any unevenness presented by the nut.

In the form shown in Figs. 3 and 4, the gripping rib 13 is continuous, and said rib follows the bodily concavity of the lock nut 10. The continuous rib engages perfectly with a faced nut. Since the rib follows the concavity of the body 10, there will be two diametrically opposite bearing lines, as will be readily understood. The gripping rib 13 is formed with an edge 14, similar to that in the construction previously described. Fig. 3 shows very clearly that the concaving of the lock nut does not produce any mutilation of the thread, which is continuous from the entrance 21* inward through the eye. hen tightened down the nut presents a level surface so that a second lock nut can be used if desired.

Having thus described my invention, I

claim as new, and desire to secure by Letters Patent,

1. A lock nut concaved bodily and having a threaded eye, the thread extending without mutilation from a single starting point at the ooncaved face of the lock nut, the said concave face having a ribbed formation presenting bearing edges at diametrically opposite sides of the eye, the said bearing edges presenting curved lines concentric with the eye of the nut.

2. A look nut, having a ribbed formation at the inner face, said ribbed formation terminating in an edge defined by an outer perpendicular wall, and a face at an acute angle to said perpendicular wall, there being an inner wall at an angle to the said face.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ISAAC D. ZITZERMAN. lVitnesses HARRY L. SHIPMAN, EDWARD D. HEATH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

